Whydoescreamgobadfasterthanbutter?Someresearchersthinkt...

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Why does cream go bad faster than butter? Some researchers think they have the answer, and it comes down to the structure of the food, not its chemical composition-a finding that could help break away from some chemicals. Cream and butter contain pretty much the same things, so why cream should go bad much faster has been a problem. Both are small globules（小球）of one liquid which spreads throughout another. The difference lies in what’s in the globules and what’s in the surrounding liquid, says Brocklehurst, who led the research. In cream, fatty globules drift about in a sea of water. In butter, globules of a watery roads are locked away in a sea of fat. The bacteria （細菌）which make the food go bad prefer to live in the watery areas of the mixture. “This means that in cream, the bacteria are free to grow throughout the mixture,” he says, “when in butter, the bacteria are locked away in locked places buried deep in the sea of fat. Trapped in this way, those colonies cannot spread and rapidly run out. They also slowly poison themselves with their waste products.” “In butter, you get a self-limiting system which stops the bacteria growing.” says Brocklehurst. The researchers are already working with food companies eager to see if their products can be made to stand bacterial attack through changes of the food’s structure.

       Brockelehurst believes it will be possible to make something used in salad cream, for instance, more like that in butter. The key will be to do this while keeping the salad cream liquid and not turning it into a solid state.

32. The significance（意義）of Brocklehurst’s rescarch is that __________.

     A. it discovered small globules in both cream and butter

    B. it suggested a way to keep some foods fresh without using some chemicals

       C. it showed the secret of how bacteria increase in cream and butter

       D. it found that cream and butter share the same chemical composition

33. According to Brocklehurst, we can keep cream fresh by ________.

       A. changing its structure                          B. killing the bacteria

       C. reducing its water                                D. removing its fat

34. The underlined word “colonies” refers to ________.

       A. tiny globules                                          B. watery regions

       C. the surrounding liquid                    D. bacteria society

35. Commercial use of the research finding will be possible if salad cream can be made to stand bacterial attack ________.

       A. by changing its chemical composition

       B. by turning it into a solid lump

       C. while its liquid form remains

       D. while keeping its structure unchanged     

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